Developing low-energy input route for conversion of methane(CH_(4))to value-added methanol(CH_(3)OH)at room temperature is important in environment and industry.Bonding in electron donor-acceptor hybrid can potentiall...Developing low-energy input route for conversion of methane(CH_(4))to value-added methanol(CH_(3)OH)at room temperature is important in environment and industry.Bonding in electron donor-acceptor hybrid can potentially promote charge transfer and photocatalytic efficiency of CH_(4) conversion.Herein,bonding in electron donor rhodamine B(RhB)-acceptor(TiO_(2))hybrid(RhB/TiO_(2))significantly promotes the selectivity of photocatalytic oxidation of CH4 to CH3OH and utilization of visible light(low-energy photons)at ambient condition.Even under green light irradiation(λ=550 nm),the noble-metal-free RhB/TiO_(2) hybrid synthesized presents enhanced oxidation of CH4 to CH_(3)OH with a generation rate of 143µmol·g^(−1)·h^(−1) and selectivity of 94%.This work demonstrates the possibility and feasibility of noble-metal-free catalysts for activating CH4 under visible light at room temperature.展开更多
Surface textures have been demonstrated to have a positive effect on the friction reduction.However,sharp edges of the normally textured patterns usually cause stress concentration and severe wear during sliding,espec...Surface textures have been demonstrated to have a positive effect on the friction reduction.However,sharp edges of the normally textured patterns usually cause stress concentration and severe wear during sliding,especially for non-conformal contacting pairs.In this study,protrusion-type textures were fabricated at different area ratios on stainless steel discs and edge profiling was performed for the protrusions,and friction tests were conducted in water to investigate the tribological properties.The results show that the friction was reduced markedly by edge profiling due to the formation of wedge contact and im provement of lubricant supply to the contact interfaces under low load.Under high load,severe wear destroyed the wedge contact resulting in high friction as those of the normally textured pairs.High area ratio exhibited better friction reduction effect.The stress analysis via ANSYS indicated that much high stress concentrated at the edges of the protrusions and could be reduced significantly by edge profiling.展开更多
基金This work was sponsored by Shanghai Pujiang Program(No.19PJ1405200)the Startup Fund for Youngman Research at SJTU(SFYR at SJTU,No.WF220516003)。
文摘Developing low-energy input route for conversion of methane(CH_(4))to value-added methanol(CH_(3)OH)at room temperature is important in environment and industry.Bonding in electron donor-acceptor hybrid can potentially promote charge transfer and photocatalytic efficiency of CH_(4) conversion.Herein,bonding in electron donor rhodamine B(RhB)-acceptor(TiO_(2))hybrid(RhB/TiO_(2))significantly promotes the selectivity of photocatalytic oxidation of CH4 to CH3OH and utilization of visible light(low-energy photons)at ambient condition.Even under green light irradiation(λ=550 nm),the noble-metal-free RhB/TiO_(2) hybrid synthesized presents enhanced oxidation of CH4 to CH_(3)OH with a generation rate of 143µmol·g^(−1)·h^(−1) and selectivity of 94%.This work demonstrates the possibility and feasibility of noble-metal-free catalysts for activating CH4 under visible light at room temperature.
文摘Surface textures have been demonstrated to have a positive effect on the friction reduction.However,sharp edges of the normally textured patterns usually cause stress concentration and severe wear during sliding,especially for non-conformal contacting pairs.In this study,protrusion-type textures were fabricated at different area ratios on stainless steel discs and edge profiling was performed for the protrusions,and friction tests were conducted in water to investigate the tribological properties.The results show that the friction was reduced markedly by edge profiling due to the formation of wedge contact and im provement of lubricant supply to the contact interfaces under low load.Under high load,severe wear destroyed the wedge contact resulting in high friction as those of the normally textured pairs.High area ratio exhibited better friction reduction effect.The stress analysis via ANSYS indicated that much high stress concentrated at the edges of the protrusions and could be reduced significantly by edge profiling.
